Automatically start/stop plugins

Have just built & started using Ardour in the last week. I've worked out how to get it to do most of what I need it to do so far but for one thing:
Is there any way to automate starting & stopping of the plugins in a track? I can think up a workaround but it would be more convenient if I could just get them to turn on & off (bypass) as is required.
Sorry for my first post being a question but apart from this, I'm loving your work on this project & wishing I had bothered trying it much earlier.
Cheers!